2009 Mercury mariner tire sizes & fitment
Approved tire and wheel sizes for the 2009 Mercury Mariner, sourced from manufacturer fitment data and refreshed monthly.
Approved fitments
| Tire size | Rim size | PCD (bolt pattern) | Offset | Load index | Speed rating |
|---|---|---|---|---|---|
| 235/70R16 OEM | R16 | N/A | N/A | N/A | N/A |
| 225/65R17 OEM | R17 | N/A | N/A | N/A | N/A |
Best by use case
Four tires, four jobs
See the best tires for the Mercury Mariner, ranked by category →
Tire recalls & safety complaints for the Mercury Mariner →
Plus-size and winter-downsize options for every Mercury Mariner factory size →
Compatible alternative sizes for 235/70R16
Sizes within the ETRTO ±3% overall-diameter safe-fit tolerance. Each row links to the size's own page.
| Alternative size | %Δ OD | Category | Verdict |
|---|---|---|---|
205/80R16 |
-0.14% | winter narrower | Safe |
215/65R18 |
0.18% | plus 2 | Safe |
235/65R17 |
0.26% | plus 1 | Safe |
235/75R15 |
-0.26% | alternative | Safe |
255/55R18 |
0.31% | plus 2 | Safe |
For the full list of alternatives with comfort/handling impact, see 235/70R16 upsize options. To check an arbitrary size pair, use the tire compatibility calculator.
Check a different size against this vehicle
Type any tire size below; we'll compute its overall-diameter delta against the OEM 235/70R16 and verdict using the ETRTO ±3% rule.
Common upgrade paths
- Plus-1: 235/65R17; one rim size up, 0.26% OD change. Sharper steering, mild ride penalty, modest cost premium.
- Plus-2: 215/65R18; two rim sizes up, 0.18% OD change. Noticeable ride penalty, higher pothole risk, meaningful tire-cost premium.
Use the plus-size calculator to evaluate any rim step against the OEM size.
How to choose tires for the 2009 mercury mariner
The 2009 Mercury Mariner ships from the factory on 235/70R16 tires mounted on R16 wheels. 2 approved fitments are documented for this model year, allowing some flexibility between performance, comfort, and winter compounds. The Compatible alternative sizes table above lists every safe substitution within the ETRTO ±3% overall-diameter tolerance.
Tire choice on the Mercury Mariner comes down to three trade-offs that matter more than brand loyalty: load index (must equal or exceed the OEM number), speed rating (must match or exceed the placard), and UTQG treadwear (higher means longer life, lower usually means stickier rubber). Owners replacing factory tires with the same compound class, for example all-season for all-season, generally see no change in ride characteristics or fuel economy. Switching categories (performance summer to all-season touring, for example) is where the trade-offs show up at the contact patch.
For 2009 Mercury Mariner owners considering a plus-size upgrade, the safer option is a Plus-1 step (one rim size up with a 10-point aspect drop and ~10 mm of additional section width). Plus-2 is technically viable on this chassis if the alternative-sizes table lists a Plus-2 candidate within tolerance, but expect a meaningful ride-harshness penalty and a tire-cost premium of 30–60% per tire relative to the OEM fitment. For winter use the recommended pattern is one width step down (e.g. from a 235 to a 225) with the aspect ratio bumped up to preserve overall diameter; narrower tires apply higher contact pressure per square inch on snow, which translates directly into shorter braking distances. The plus-size calculator evaluates any specific rim step against this OEM size.
Before purchasing, verify the tire size on the driver-door placard of your specific 2009 Mercury Mariner, since trim levels and option packages can shift the original fitment from what is documented here. The placard reading is the authoritative source per FMVSS 110, and dealers will reference the placard rather than aftermarket catalogs when validating warranty claims.
NHTSA-reported issues for 2009 mercury mariner
Top issue category: Tires (General)
Most reported: Tires (General) (12) · Sidewall (1) · Valve (1)
Reported across: 2005 – 2008 (4 years)
What owners described
Cracking or dry rot appears in 29% of these reports; about 3.1× as often as across all tire complaints. Percentages are shares of the 14 reports covering every model year of the Mercury Mariner that include a written account; a single report can describe more than one problem, so they do not total 100%.
| Reported problem | This subject | All tire complaints | Relative |
|---|---|---|---|
| Cracking or dry rot | 29% | 9% | 3.1× |
| Tread or belt separation | 14% | 13% | 1.1× |
| Blowout or sudden deflation | 7% | 20% | 0.4× |
| Sidewall failure | 7% | 15% | 0.5× |
Mileage at failure
5 of these reports state an odometer reading. The middle report is at 12,000 miles, with 8 in 10 falling between 2,000 and 25,000 miles.
In owners' own words
Verbatim excerpts from complaints filed with NHTSA about Mercury Mariner. Reports are published by NHTSA as filed and are lightly cleaned here only to remove intake codes.
I DROVE FROM ATLANTA, GEORGIA TO EL PASO, TEXAS OVER A TWO DAY PERIOD. I WAS NOT SPEEDING AND THERE WERE NO ADVERSE WEATHER CONDITIONS. PREPARING FOR MY RETURN TRIP, I TOOK MY CAR TO GET AN OIL CHANGE. THE MECHANIC DISCOVERED MY TIRE HAD SEVERE TREAD SEPARATION. THE TIRE HAS NOT YET BEEN REPAIRED OR REPLACED, THOUGH THE CAR IS NOW USING A DONUT TIRE IN ITS PLACE.
THE CONTACT OWNS A 2005 MERCURY MARINER. THE VEHICLE HAS CONTITRAC AW, SIZE P27560R17 TIRES. THE CONTACT STATED THAT THE TIRES ON THE VEHICLE WERE EXTREMELY NOISY, THE TREAD WAS CUPPING, AND THERE WERE HAIRLINE CRACKS IN THE SIDEWALL WHERE THE RUBBER MEETS THE RIM. THE NOISE IS LOUD AT ALL SPEEDS, BUT INTENSIFIES WHILE DRIVING 5 - 65 MPH. THE TIRES HAVE BEEN ROTATED AND ALIGNED BY BOTH THE DEALER AND AN INDEPENDENT TIRE STORE. THE NOISE WORSENED AFTER THE TIRES WERE ROTATED AND ALIGNED. THE CONTACT PLANS TO PURCHASE NEW TIRES BECAUSE HIS WIFE IS AFRAID TO DRIVE THE VEHICLE. THE CURRENT MILEAGE WAS 25,000 AND FAILURE MILEAGE WAS 4,000.
IN JULY 2008, "CHECK TIRE PRESSURE" LIGHT BECAME PRESENT. UPON PLACING AIR IN LEFT-REAR TIRE A CRACK/ LEAK IN VALVE STEM BECAME PRESENT. VALVE STEM WAS REPLACED. IN AUGUST 2008 SAME ISSUE OCCURRED WITH RIGHT REAR STEM. TODAY, OCTOBER 26TH 2008 THE ISSUE OCCURRED WITH THE RIGHT FRONT VALVE STEM. ALL VALVE STEMS ON MY VEHICLE HAVE NOW BEEN REPLACED.
ON JULY 5, 2009 WHILE DRIVING MY MERCURY MARINER THE PASSENGER SIDE REAR TIRE WENT FLAT. CAUSE WAS A BAD VALVE STEM; ON SEPTEMBER 4, 2009 I HAD THE SAME PROBLEM WITH THE DRIVER SIDE REAR TIRE. THE AUTO TECH AT WALL MART SHOWED ME THE VALVE STEM WAS DRY ROTTED AND HAD TO BE REPLACED. I ALSO HAD HIM REPLACE BOTH VALVE STEMS ON THE FRONT TIRES, WHICH ALSO SHOWED SIGNS OF DRY ROT.
Complaints are voluntarily submitted to the NHTSA Office of Defects Investigation and are not verified by NHTSA; they represent owner-reported problems, not proven defects. Counts can be useful as a relative quality signal across comparable tires or vehicles.
Frequently asked questions
What size tires fit a 2009 Mercury Mariner?
Can I run a different tire size on my 2009 Mercury Mariner?
Where can I buy tires for my 2009 Mercury Mariner?
What is the recommended tire pressure for the 2009 Mercury Mariner?
Can I fit winter tires in a different size on my 2009 Mercury Mariner?
How often should I rotate the tires on my 2009 Mercury Mariner?
For broader tire questions; replacement timing, UTQG, EV-specific tires, winter swaps; see the tire FAQ.
Sources for this page
- Vehicle owner's manual tire & wheel placard; door-jamb placard on the Mercury Mariner is the authoritative source for OEM tire size, load index, and cold-inflation pressure for your specific trim.
- NHTSA SaferCar; recall lookup for the 2009 Mercury Mariner.
- ETRTO 2024 Standards Manual §2.3; overall-diameter math used for the alternative-size verdicts above.
- Tire & Rim Association 2025 Yearbook; load-index to maximum-load reference.
Last verified 2026-10-07.